ADE is very good at generating error message that have no meaning to any normal person (or indeed to anyone who doesn't have access to the ADE source code).
Also, it often generates messages that are clear but completely incorrect.
It could be reated to e_adept_request_expired. In that case, check that the time and timezone on your computer are correct,
and also on any connected eReader device that remembers time.
Otherwise, a general comment that may help ....
There are lots of bugs in ADE2.0. Try replacing ADE2.0 with the older but more reliable v1.7.2.
(You can have them both installed at once if you like.)
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172